PRT Y-Rails

[JMCS]

Looking for help adjusting my y-rails. Ordered new rails with from Shopbot with the hardenend v-rails already installed. My problem is- rail ends not parallel, shimmed both ends, good to go. All four v-wheels sit perfect. As I roll the carriage across the y, the two closest wheels (x0,y0) ride across perfect. On the far side, I get one wheel that rides up on the rail. I tried shimming the wheels, track, ect. All it does is move what wheel rides up the rail. I'm thinking there is a small bend in the new rails? Any suggestions?

[Gary Campbell]

Assuming the Y rails are in fact perfectly parallel, a wheel "riding up" is a result of the 2 Y rails not being orthogonal, i.e., not in the same plane. Which can result from the X rails being in the same condition, which twists the X car. With the Y car removed, this is usually visible to the trained eye.

When setup properly, you cant believe how smooth one of these old machines runs on the hardened rails.